Seal Actuated or Maintained by Differential Pressure

ABSTRACT

A seal has a tight sealing between a first space and a second space. The second space is at least partially enclosed by a member. The apparatus includes or performs creating or maintaining a pressure difference between a pressure in a third space at a seal assembly and pressure in each of the first space and the second space; and pushing, caused by the pressure difference, against a seal in the seal assembly to tighten sealing provided by the seal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation of U.S. patent applicationSer. No. 10/654,599, filed Sep. 2, 2003, which is incorporated byreference along with all other references cited in this application.

BACKGROUND OF THE INVENTION

The present invention relates to seals. Embodiments of the presentinvention are especially suited for use in leak-resistant (e.g.,leak-proof) coupling of pieces made of different materials, including,for example, coupling of quartz or glass tubing with metal tubing, forexample, in the production of materials or electronic devices.

Seals are needed in a variety of fields. For example, seals are neededin equipment for gas or liquid handling, electronics, and materials. Forexample, chemical vapor deposition (CVD), laser vaporization, and othermethods for the fabrication of materials and nanostructures often use aquartz tube and a heat source, where the quartz tube needs to beconnected to inlet or outlet gas lines in a leak-proof manner. A wellconstructed, carefully arranged and carefully operated conventionalquartz-to-metal connection can sometimes accomplish such leak-proofconnection. However, such a conventional quartz-to-metal connection canbe relatively expensive, require that the pieces being connected aremade with relatively high precision, and require care to set up andoperate if leaks are to be successfully avoided.

Various metal-to-metal connections are known and can be leak-proof.Threaded metal connections, metal gaskets under compression betweentightened flanges, and metal welds give quality seals. In U.S. Pat. No.4,121,859, DeMey describes a metal-to-metal seal using a gasket ofresilient material that is compressed by clamps. The gasket materialforms a leak-proof seal and precludes voids at the sealing interface. InU.S. Pat. No. 5,131,695, Wiser describes an improved connection forjoining two conduits with a compressed variable washer formed frompolytetrafluoroethylene (Teflon) and some percentage of glass fiber. Astop shoulder prevents over-tightening of the washer. The connection isprimarily for refrigeration systems and is reusable. While these schemesdo yield leak-proof seals, they are generally for connecting metallicmembers to metallic members and for connecting members of like materialsto each other.

In U.S. Pat. No. 4,955,522, Stuhler presents a process for theleak-proof joining of ceramic sealing discs to metallic attachments. Theceramic sealing surface may be active soldered or metallized thensoldered to the metallic attachment. This method can form a leak-proofseal between dissimilar materials, but the seal cannot practically bere-used because the soldered seal is effectively a permanent seal.Similarly, quartz or glass can be permanently welded to a metallicattachment, but such a connection is again not readily reusable orreadily changeable and can be expensive.

A gas-tight seal that can be used in elevated temperatures and thermalcycles to join tubes of dissimilar materials is described by Rynders etal. in U.S. Pat. No. 6,302,402. The described seal is particularly forsealing a metallic tube to a ceramic tube. The seal of Rynders et al.can work only when the entire seal assembly is in a pressurized chamberin which the chamber pressure is greater than the pressure within thetubes being joined. The seal is impractical and inflexible for manyapplications at least because of its need to be within a chamber havingpressure that is greater than the pressure within the tubes beingjoined.

For quartz to metal connections, a single O-ring in a metal housing isfrequently used in a conventional manner. However, it is difficult toconsistently reproduce reliably gas-tight and leak-proof seals using asingle O-ring in a conventional manner. Disproportionate forces andvariations in surface features at the sealing interface can producevoids and preclude a complete seal.

A taper seal, such as at the end of a quartz tube and opening of acomplementary metal member can produce good seals, but can be expensivedue to the required tolerances in machining both members to be joined.Integration of O-rings into the taper seal does improve the sealing, butreproducible and complete sealing is still difficult to achieve on aconsistent basis.

BRIEF SUMMARY OF THE INVENTION

What is needed is an improved sealing scheme and associated methods. Forexample, what is needed are solutions that can overcome at least some ofthe deficiencies of conventional seals, for example, some of thedeficiencies mentioned above.

According to an embodiment of the present invention, there is anapparatus for combining with at least a seal to seal a member. When themember is to be sealed, the member is at least partially in a firstspace and at least partially encloses at least a portion of a secondspace, the member including an opening to the second space. Theapparatus comprises a housing configured to define, at least partially,a third space. The housing is configured to facilitate maintainingpressure level in the third space other than merely by exposing thethird space to the first space or to the second space. A pressuredifference between the third space and at least one of the first spaceor the second space creates a force on the seal that promotes tightnessof sealing provided by the seal.

According to another embodiment of the present invention, there is amethod for tight sealing between a first space and a second space, thesecond space being at least partially enclosed by a member. The methodcomprises creating a pressure difference between a pressure in a thirdspace at a seal assembly and pressure in each of the first space and thesecond space; and pushing, caused by the pressure difference, against aseal in the seal assembly to tighten sealing provided by the seal.

According to another embodiment of the present invention, there is anapparatus for monitoring seal quality. The apparatus includes a housing,a sensor, and an indicator. The housing is configured to contain, atleast partially, a space, pressure level within the space beingindicative of reliability or quality of sealing in a seal. The sensor isone that is responsive to the pressure level or a change in the pressurelevel. The indicator is configured to convey information indicative ofreliability or quality of sealing in the seal.

According to one embodiment of the present invention, there is a methodfor monitoring seal quality. The method includes maintaining a pressurelevel in a space, the pressure level being indicative of the reliabilityor quality of sealing in a seal; monitoring the pressure level; andproviding an indicator based on the monitoring of the pressure level.

Other objects, features, and advantages of the present invention willbecome apparent upon consideration of the following detailed descriptionand the accompanying drawings, in which like reference designationsrepresent like features throughout the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more extensively describe some embodiments of the presentinvention, reference is made to the accompanying drawings. Thesedrawings are not to be considered limitations in the scope of theinvention, but are merely illustrative.

FIG. 1 is a schematic section view showing an end of a first tube and anend of a fitting or second tube that is to be sealed to the first tube.

FIG. 2 is a schematic concept view showing an end of a first member andan end of a fitting or second member being sealed to the first memberaccording to an embodiment of the present invention.

FIGS. 3A and 3B are schematic section views showing different stages ofsealing, according to an embodiment of the present invention.

FIG. 4 is a schematic concept view showing a coupler, according to anembodiment of the present invention, and a first and a second member,wherein the coupler facilitates sealing the first member to the secondmember.

FIG. 5A is a schematic exterior view showing an embodiment of thecoupler of FIG. 4, in one example operating environment.

FIG. 5B is a schematic section view showing the coupler of FIG. 5A.

FIG. 5C is a schematic section view, perpendicular to the view of FIG.5B, showing the coupler of FIGS. 5A and 5B.

FIG. 6A is a schematic flowchart indicating a sealing method accordingto an embodiment of the present invention.

FIG. 6B is a schematic flowchart indicating a seal-quality monitoringmethod according to an embodiment of the present invention.

FIGS. 7A-7F are schematic section views each showing the end of a firstmember and the end of a fitting or second member to be sealed to thefirst member according to various embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The description above and below and the drawings of the present documentrefer to examples of currently described embodiments of the presentinvention and also describe some exemplary optional features and/oralternative embodiments. It will be understood that the embodimentsreferred to are for the purpose of illustration and are not intended tolimit the invention specifically to those embodiments. On the contrary,the invention is intended to cover alternatives, variations,modifications and equivalents and anything that is included within thespirit and scope of the invention.

What is needed is a reusable and highly leak-resistant (e.g.,leak-proof) seal assembly, and associated methods. Especially needed isfor the seal assembly to be economical and suited for use in sealing ajunction between dissimilar materials such as quartz and metal or glassand metal. Preferably, the seal assembly is able to withstand elevatedtemperatures, multiple thermal cycles, and/or operate in variousenvironments. It is also desired that the seal assembly has, or is ableto accommodate, a readily noticeable indicator of the status of theseal. Various embodiments of the present invention help satisfy varioussubsets of these needs.

FIG. 1 is a schematic section view showing an end 10 of a first tube 12and an end 14 of a fitting 16 or second tube 16 that may be sought to besealed to the first tube 12. No particular sealing mechanism is shown inFIG. 1.

FIG. 2 is a schematic concept view showing sealing, according to someembodiments of the present invention, between a first member 12 a and afitting 16 a or second member 16 a. The first member 12 a is at leastpartially in a first space 18. The fitting 16 a or second member 16 a atleast partially encloses a second space 20. Note that the first member12 a also at least partially encloses the second space 20. An arrow 22schematically indicates that pressure is added to or removed from somelocation at a portion 24 of the fitting 16 a or second member 16 a totighten a sealing 26 against the first member 12 a. A pressure level ismaintained, at the location, that differs from pressure level in thefirst space 18 and/or pressure level in the second space 20. Thedifference in pressure exerts a force on a seal to tighten the sealing26, for example, to make the sealing 26 leak-proof. The fitting 16 a maybe, for example, a coupler, e.g., as shown in FIG. 4 or 5A-5C.

FIGS. 3A and 3B are schematic section views showing different stages ofsealing, according to an embodiment of the present invention. FIG. 3Ashows an end of a first member 12 b, and a structure 28 that is part ofa fitting 16 b or a second member 16 b. The first member 12 b is atleast partially in an environmental space 18 a. Both the first member 12b and the fitting 16 b or second member 16 b at least partially enclosean internal space 20 a. In the simple configuration shown in FIG. 3A,the first member 12 b is simply a tube, and the structure 28 surrounds asegment of the first member 12 b. The structure 28 helps to define aseal space 30. A plug or valve 32 (shown schematically) also helps todefine or partially close off the seal space 30. The seal space may alsobe referred to as the third space 30, to continue the terminology ofFIG. 2 (“first space 18” and “second space 20”). A first seal 34 and asecond seal 36 also each surround a segment of the first member 12 b.The seals 34 and 36 may be, for example, O-rings. A sensor 31 (e.g., apressure sensor) senses the status of the seal, and an indicator 33indicates the status of the seal. A mechanical element 35 can switchablyapply a mechanical force on the seals 34 and 36 to disrupt sealingprovided by the seals.

In the state shown in FIG. 3A, the first seal 34 does not (yet) tightlyseal the seal space 30 from the environmental space 18 a. Similarly, thesecond seal 36 does not (yet) tightly seal the seal space 30 from theinternal space 20 a. As shown, the seals 34 and 36 do not (yet) togethertightly seal the internal space 20 a from the environmental space 18 a.

FIG. 3B is a schematic section view showing the elements from FIG. 3Aunder tight sealing, and undergoing tightening sealing, according to theembodiment of FIGS. 3A and 3B of the present invention. A nozzle 38 hasbeen coupled, e.g., at least temporarily, to the structure 28. Thenozzle 38 has provided, and is providing, suction to the seal space 30,as indicated by an arrow 40. The suction may be being provided via thenozzle 38 by a pump or reservoir. The suction in the seal space 30“pulls” on the seals 34 and 36 and moves them into contact or intotighter contact with the structure 28, or both, and with the firstmember 12 b. For example, the structure may have a feature 42 thatleaves a gap against the member 12 b, and the gaps are plugged by theseal when the seal is “pulled” by the suction toward the gap. Feature 42may be, for example, protrusions or lips or the like or any othercompetent feature. (Of course, “pulling” by suction is merely aconvenient way of referring to the pushing by a pressure that is madedominant by the suction.) Preferably, the valve 32 of FIG. 3A can beclosed to maintain the tightened seal even after the nozzle 38 (and thepump or reservoir) has been decoupled from the structure 28.

The arrangement shown for demonstration in FIGS. 3A and 3B is an exampleof one in which pressure in the seal space 30 is capable of beingmaintained that differs from both pressure in the environmental space 18a and pressure in the internal space 20 a. The seal space is defined, atleast in part, by an external wall of the member and an internal wall ofthe structure 28. The arrangement is especially beneficial when thefirst member 12 b is made of a different material as another member thatis to be coupled to the first member. The other member is, e.g., thesecond member 16 b itself or a non-shown member that is coupled (notshown) to the fitting 16 b. For example, the non-shown member may be ofmetal and may be connected to a metal fitting 16 b using anymetal-to-metal connection. For example, the first member 12 b may bemade of quartz, glass, ceramic, plastic, or the like, or any othernon-metal material, or a combination thereof. For example, the firstmember 12 b may be a quartz tube. The fitting 16 b or second member 16 bmay couple to, or include a stopper, plug, end piece, or blank, so as toclose and seal the opening of the second member 16 b.

FIG. 4 is a schematic concept view showing a coupler 44, according to anembodiment of the present invention, and a first member 12 c and asecond member 16 c. The coupler 44 facilitates sealing the first member12 c to the second member 16 c. In operation, the coupler 44 is sealedto the first member 12 c and is sealed to the second member 16 c, andthe first member 12 c is so coupled to the member 16 c.

FIG. 5A is a schematic exterior view showing a particular embodiment 46of the coupler 44 of FIG. 4, in one example operating environment. Thecoupler 46 is also a particular embodiment of the sealing assembly shownin FIGS. 3A and 3B. A first member 12 d is to be coupled to a secondmember 16 d. In the example operating environment of FIG. 5A, the firstmember 12 d may be, for example, a quartz tube coupled to a furnace 48.

FIG. 5B is a schematic section view showing the coupler of FIG. 5A. Thesection is along a radial plane relative to a longitudinal axis of thefirst member 12 d, as indicated in FIG. 5A. FIG. 5C is a schematicsection view, perpendicular to the view of FIG. 5B, as indicated by asection line in FIG. 5B. FIG. 5C shows the coupler of FIGS. 5A and 5B.

As shown in FIG. 5C, there is an environmental space 18 b, the firstmember 12 d partially encloses an internal space 20 b, and a structure52 partially defines and encloses a seal space 30 a. The structure 52may also be referred to as the housing 52. Operation of the coupler 46is as has been discussed in connection with FIGS. 3A and 3B, and isunderstood by comparing FIG. 5C to FIG. 3B.

Preferably, there is a first end piece 50 and a second end piece 54 thateach help keep the seals 34 a and 36 a in sufficient proximity to theseal space 30 a for the anticipated level of evacuation of the sealspace 30 a to “pull” the seals 34 a and 36 a into tight sealingposition. Thus, the end pieces 50 and 54 can free a human techniciansetting up the coupler 46 from having to manually position the seals 34a and 36 a next to the structure or housing 52. Further the end pieces50 and 54 can prevent the seals 34 a and 36 a from being blown too faraway for re-tightening when the seals 34 a and 36 a are sought to beloosened by a burst of gas or fluid into the seal space 30 a. The endpieces 50 and 54 may be separate pieces from the structure or housing52, or they may be removably or permanently connected to the structureor housing 52 by any mechanism whatsoever, for example, threading,friction, bonding, welding, spring force, or the like, or any othercompetent mechanism. In FIG. 5C, the end pieces 50 and 54 are boththreaded onto matching threads in the structure or housing 52. Notethat, in general, the annular “groove” in which the seals 34 a and 36 aare situated can be allowed to be large enough such that the seals 34 aand 36 a can shift around slightly, as long as the suction is strongenough to pull and hold the seals 34 a and 36 a tightly to the sealingsurfaces against which the seals 34 a and 36 a are to seal. However, inthe embodiment shown in FIG. 5C, the end pieces 50 and 54 can bethreaded far enough into the structure or housing 52 that the “groove”constrains the seals 34 a and 36 a, even before suction is applied, suchthat the end pieces 50 and 54 cause the seals 34 a and 36 a to alreadytouch the surfaces against which the seals 34 a and 36 a are to make aseal, even before suction is applied.

According to one embodiment of the coupler as particularly shown inFIGS. 5A to 5C, there a seal assembly that includes two O-rings as seals34 a and 36 a, a first end piece 50, a seal structure or housing 52, anda second end piece 54 having central channels in whole or in part. Twomembers 12 and 16 are to be joined by the coupler. The coupler isconfigured to be moved, selectively positioned and connected to themembers being joined. One O-ring 34 a is positioned between the firstend piece 50 and the seal structure or housing 52 of the seal assembly.The seal assembly may refer to either the combined pieces of the sealhousing or the entire seal element, including, e.g., the O-rings. Thesecond O-ring 36 a is positioned between the seal structure or housing52 and second end piece 54 of the seal assembly, and there exists avolume 30 a contained by the two O-rings 34 a and 36 a, the attachedmember 12, and the seal structure or housing 52.

There is an opening to this small volume 30 a in the seal structure orhousing 52 through which means can be applied to evacuate the volume tolow pressure or vacuum. The low pressure or vacuum places an inwardforce on the two O-rings 34 a and 36 a, which causes them to form a leakproof seal with the seal structure or housing 52 and attached member 12.In this way, the seal is actuated by pressure differential and a plug orshut-off valve 32 (as shown in FIG. 3A) at or connected to the openingon the seal structure or housing 52 is used to hold the pressuredifferential and maintain the leak-proof seal. The valve can beelectively released to electively cease to promote tightness of sealingprovided by the leak proof seal. The valve 32 can be any type ofcompetent valve, for example, a valve that automatically closes uponwithdrawal of the suction or pressure nozzle from the seal assembly.Generally, the valve 32 may be a check valve, a manual valve, or anyother competent valve, whether it uses spring-loading, balls, disks, orwhatever other competent mechanisms. Valves are well known.

The O-rings can be plastic, rubber, silicone, Teflon, nitrile, Viton,fluorosilicone, neoprene, Kalrez, polyurethane, vulcanized, metal, orthe like, or any other competent material, or a combination ofmaterials. The members to be joined can be of like or dissimilarmaterials, including metal, quartz, glass, ceramic, plastic, or othermaterial. The members can be cylindrical, tubular, ellipsoidal or othershape, and one of the members can be a plug, stopper, end-piece, orblank. One or all of the members may be able to hold fluid or gas,either statically or flowing. The leak-proof seal may be opened orunsealed by opening the small volume contained by the O-rings, attachedmember, and second piece to atmosphere or gases such as compressed air,nitrogen, argon, helium, hydrogen, or other gas.

The small volume may also be pressurized to higher than environmentalpressure, e.g., higher than atmospheric pressure, to open the seal. Thishigher pressure may be restricted to be below a certain amount, e.g.,below 200 pounds per square inch. The pressurization removes the inwardforces on the O-rings and allows the members to be more easilyseparated. In one embodiment, the coupler is for use in an environmentwherein chemicals are present, and the pressurization is by gas or fluidthat comprises an inert gas or fluid that does not react with thechemicals.

The seal is reusable and through selection of materials for the sealassembly and O-rings, can operate in elevated temperatures, multiplethermal cycles, toxic gas or material environments, flammable gasenvironments, and in various pressure environments. Either or bothO-rings can be intentionally configured, e.g., sized, such that if theyare not being tightened by suction, then they will not provideleak-proof sealing. An O-ring is an example of a seal that, whensectioned cross to the O-ring's axis into a planar ring shape, has anexternal periphery having only positive curvature. The planar ring shapemay be called an axial cross section.

The coupler can include a sensor and an indicator of the status of theseal. The indication can reveal that the seal is in operation andleak-proof or that it is opened and unsealed. The indicator can bevisual, such as by LED, a flashing light source, an analogue or digitalgauge, an extending or retracting button, or a color change, or the likeor any other competent mechanism. The indicator can also be audio, e.g.,a buzzer or bell or voice announcement or alarm, or the like or anyother competent mechanism, or a combination of visual and audio or anyother sensory input. The sensor can be a sensor of the pressure level inthe seal space. The indicator can be a continuous indicator and/or analarm that is raised, or is made especially apparent, in case of sealfailure. The sensor can also include a wired or wireless transmitterthat sends signals to a monitoring computer or pager or telephone, orthe like.

A push-rod, slide, or other device can be used to open the O-ring seal.This may be used when the seal does not easily unseal after the volumecontained by the two O-rings, the attached member, and the second pieceis opened to atmospheric pressure or higher pressure. A mechanical forceis imparted on the O-rings, attached member, or seal assembly to breakthe leak-proof seal.

According to another embodiment, the seal assembly is configured so thatthe small volume contained by the O-rings, the attached member, and thesecond piece is pressurized to place an outward force on the O-rings.The O-rings are forced against the seal assembly (housing) and theattached member to form the leak-proof seal. The seal is actuated by thedifferential pressure between the higher pressure in the small containedvolume and the outside pressure.

In some embodiments of the invention, the seal housing is be configuredso that only one O-ring or other type of seal is needed, where theO-ring is tightly fit between two pieces of the housing with the smallopen volume above it. This small volume is pressurized and the O-ring isforced against the attached member to form the leak-proof seal.

According to a specific embodiment of the invention, a leak-proof sealassembly is used for connecting quartz, glass, ceramic, or plastic tometal and is used for the production of materials and nanostructures.The nanostructures include nanowires, nanotubes, carbon nanotubes,nanoparticles, or thin films of materials where at least one of thedimensions of the structures is less than 100 nanometers. Thenanostructures may be produced by chemical vapor deposition, laservaporization, and other known method. These techniques can utilize theleak-proof seals to add control, eliminate contamination and safetyproblems, and achieve more reproducible results. More specifically, forthe synthesis of carbon nanotubes, the leak-proof seal precludes oxygenor air leaks at the sealing interfaces. This is a very important concernfor quality synthesis of the carbon nanotubes at high temperatures,where oxygen can damage or destroy the carbon nanotubes and hinder orcompletely prevent synthesis.

Generally, seal assemblies according to embodiments of the presentinvention may be large or small, as appropriate to the member or membersbeing sealed. According to a specific embodiment, the leak-proof sealassembly is used for connecting tubing or other members having anoutside diameter that is no less than ⅛ inch. For example, the centralchannel of a coupler according to the embodiment is no less than ⅛ inch.Couplers can also be restricted to couple members having a diameter thatis less than, for example, 16 inches.

According to an embodiment of the invention, a reusable leak-proof sealapparatus for connecting multiple members is provided that includes twoO-rings and a seal assembly housing. The volume is contained between thetwo O-rings, one of the members, and the seal assembly housing. Thisvolume is evacuated to low pressure or to vacuum, which results in aninward force on the O-rings and forms a leak-proof and gas-tight seal.The present invention is especially suited for quartz or glass to metalconnections, such as in some heated furnace equipment setups. The sealassembly may include an indicator of the nature of the seal,particularly whether it is closed and fluid-tight or open and unsealed.In an alternative embodiment, the volume is pressurized and an outwardforce on the O-rings brings about the differential pressure actuatedseal.

FIG. 6A is a schematic flowchart indicating a sealing method 70according to an embodiment of the present invention. In a step 72, aseal assembly is coupled to a member. For example, the seal assembly maybe an embodiment of the present invention as is discussed in the presentdocument. In a step 74, a pressure difference is created at the sealassembly to tighten sealing of the member. In a step 76, the pressuredifference is electively reduced or eliminated or reversed to ceasetightening sealing of the member, which is one exemplary way toelectively cease to promote a tightness of sealing.

FIG. 6B is a schematic flowchart indicating a method 80 for monitoringseal quality according to an embodiment of the present invention. In astep 82, a pressure level is established in a space. The pressure levelis indicative of the reliability or quality of sealing in a seal. Forexample, the pressure level may be the pressure level in the seal spacediscussed in connection with FIGS. 3A, 3B, 5A, and 5B. In a step 84, thepressure level is monitored. In a step 86, an indicator is providedbased on the monitoring of the pressure level from the step 84.

FIGS. 7A-7F are schematic section views each showing the end of a firstmember and the end of a fitting or second member to be sealed to thefirst member according to various embodiments of the present invention.

In FIG. 7A, an embodiment of the seal assembly of FIGS. 3A and 3B isshown in which seals 34 b and 36 b are not O-rings but are seals havinga concave surface, such as described in U.S. Pat. No. 6,302,402, toRynders et al., which is incorporated by reference. Pressure applied tothe concave surface tends to flex the seals in a manner tending toreduce the concavity of the surface. This flex tightens the seals.

In FIG. 7B, a seal assembly creates a pressure difference by applyinghigh pressure, and not suction, to a seal space. The high pressurepushes two seals 34 c, shown as O-rings, tighter against gaps betweenthe seal housing and the member being sealed.

In FIG. 7C, a seal assembly also creates a pressure difference byapplying high pressure, and not suction, to a seal space. FIG. 7C showsthat, instead of two separate seals, such as two O-rings, a single seal(or two mutually linked seals) may be used. The single seal shown is onethat has a bowed cross section. The pressure difference tends to unbowthe seal, to thereby tighten both the sealing between the environmentalspace and the seal space and also the sealing between the internal spaceand the seal space. FIG. 7D shows another embodiment of the sealassembly discussed in connection with FIG. 7C. The seal assembly of FIG.7D is shown as using a seal such as the seals taught in the incorporatedU.S. Pat. No. 6,302,402, to Rynders et al.

In FIG. 7E, a seal assembly receives pressure into its seal space notdirectly via an external opening in the seal-space housing 16 e.Instead, the seal assembly receives its pressure via a channel 62 thatis defined by a member 12 e that is being sealed. Similarly, forsuction-based seal assemblies according to the present invention, thepressure received can be negative pressure, or suction, and thus theseal space can be evacuated from such a channel.

Actually, in FIG. 7E, the shown portion of member 12 e can be thought ofas a portion of an embodiment of a coupler 44 of FIG. 4, and seal-spacehousing 16 e can be thought of as a member that is being sealed that hashad an internal groove scored into its interior wall, near its openingedge. More generally, in the drawings of the present document, thefeatures of the seal housing or second member may instead be consideredto be features of the first member, and vice versa.

In FIG. 7F, a seal assembly is shown that creates a seal against aninternal wall of a member 12 f that is being sealed. The seal assemblyshown is a suction-based embodiment using O-rings, but of course otherembodiments may also similarly be configured to use the interior of themember 12 f for sealing. For example, the seal assembly is a throughcoupler, but an end-cap embodiment can also be used that is closed atthe bottom of FIG. 7F.

This description of the invention has been presented for the purposes ofillustration and description. It is not intended to be exhaustive or tolimit the invention to the precise form described, and manymodifications and variations are possible in light of the teachingabove. The embodiments were chosen and described in order to bestexplain the principles of the invention and its practical applications.This description will enable others skilled in the art to best utilizeand practice the invention in various embodiments and with variousmodifications as are suited to a particular use. The scope of theinvention is defined by the following claims.

1. A method of creating a seal comprising: providing a first memberhaving an end with a first opening, and a first wall with a firstinterior side and first exterior side, wherein the first opening isadapted to accept a second member and the seal is created between thefirst member and the second member; placing a first sealing memberagainst the first interior side of the first member a first distancefrom the first opening; placing a second sealing member against thefirst interior side of the first member a second distance from the firstopening, wherein the second distance is greater than the first distance;and forming a second opening in the first wall at a third distance fromthe first opening, wherein the third distance is between the first sealmember and second seal member.
 2. The method of claim 1 wherein thesecond opening couples to a pressure measuring device.
 3. The method ofclaim 1 comprising: inserting the second member into the first member sothat the first and second sealing members contact a second exterior sideof the second member, thereby forming a sealing space between the firstand second sealing members and between the second exterior side of thesecond member and; and via the second opening, reducing a pressure thesealing space to a first pressure level.
 4. The method of claim 1wherein the first opening is circular and the second member iscylindrical.
 5. The method of claim 1 wherein the first sealing memberis an O-ring and the second sealing member is an O-ring.
 6. The methodof claim 1 wherein a pump is coupled to the second opening.
 7. Themethod of claim 3 wherein the first pressure level of the sealing spaceis less than a second pressure level of a first space contacting thefirst exterior side of the first member and less than a third pressurelevel of a second space contacting a second interior side of the secondmember.
 8. The method of claim 3 wherein the sealing space forms anannular ring around the second exterior side of the second member. 9.The method of claim 1 comprising: forming a third opening in the firstwall at a fourth distance from the first opening, wherein the fourthdistance is between the first seal member and second seal member; viathe second opening, reducing a pressure of the seal to a first pressurelevel; and via the third opening, monitoring the first pressure level ofthe seal.
 10. The method of claim 1 comprising: via the second opening,reducing a pressure of the seal to a first pressure level which ishigher than a pressure contacting the first exterior side of the firstmember.
 11. The method of claim 1 comprising: via the second opening,reducing a pressure of the seal to a first pressure level which is lowerthan a pressure contacting the first exterior side of the first member.12. A seal apparatus comprising: an end of the apparatus with a firstopening, wherein the first opening is adapted to accept a first memberto which the seal apparatus will seal with; an interior surface of theseal apparatus which extends to the end of the apparatus; a first groovein the interior surface at a first distance from the end of theapparatus; a second groove in the interior surface at a second distancefrom the end of the apparatus, wherein the second distance is greaterthan the first distance; a first sealing component, positioned in andadapted to fit into the first groove; a second sealing component,positioned in and adapted to fit into the second groove; and a secondopening in the interior surface of the seal apparatus at a thirddistance from the end of the seal apparatus, wherein the third distanceis between the first and second distances.
 13. The apparatus of claim 12comprising: a pump, coupled via a passageway to the second opening. 14.The apparatus of claim 12 wherein the second opening is transverse tothe first opening.
 15. The apparatus of claim 12 comprising: a thirdopening in the interior surface of the seal apparatus at a fourthdistance from the end of the seal apparatus, wherein the fourth distanceis between the first and second distances.
 16. The apparatus of claim 12wherein the first member has a tubular shape.
 17. The apparatus of claim12 wherein the first opening is coupled to a first passageway surroundedby the interior surface of the seal apparatus.
 18. The apparatus ofclaim 12 wherein the first and second sealing components are O-rings.19. A seal apparatus comprising: an end of the apparatus with a firstopening, wherein the first opening is adapted to accept a first memberto which the seal apparatus will seal with; an interior surface of theseal apparatus which extends to the end of the apparatus; a groove inthe interior surface, the groove extending a first distance from the endof the apparatus to a second distance from the end of the apparatus; asealing component, positioned in and adapted to fit into the groove; anda second opening in the groove of the seal apparatus at a third distancefrom the end of the seal apparatus, wherein the third distance isbetween the first and second distances.
 20. The seal apparatus of claim19 wherein the sealing apparatus is U shaped.